Process and headbox of a machine for producing a fibrous material web

Abstract

Process for forming and a headbox for producing a fibrous material web from a pulp suspension to form one of a paper or cardboard web. The headbox includes a headbox nozzle and at least one lamella, and the process includes providing a structured surface with at least one structure one of in and on a surface of the at least one lamella, such that the structured surface is arranged to generate cross flows inside the pulp suspension, whereby the cross flows lead to shear flows in the suspension stream.

What is claimed:  
     
         1 . A process for producing a fibrous material web from a pulp suspension that is supplied from a headbox having a headbox nozzle with at least one lamella, the process comprising: 
 supplying a pulp suspension stream toward the headbox nozzle; and    generating cross flows inside the pulp suspension stream due to structures one of in and on a surface of the at least one lamella, whereby the cross flows lead to shear flows in the suspension stream.    
     
     
         2 . A process for forming a headbox for producing a fibrous material web from a pulp suspension to form one of a paper or cardboard web, the headbox including a headbox nozzle and at least one lamella, the process comprising: 
 providing a structured surface with at least one structure one of in and on a surface of the at least one lamella, wherein the structured surface is arranged to generate cross flows inside the pulp suspension, whereby the cross flows lead to shear flows in the suspension stream.    
     
     
         3 . The process in accordance with  claim 2 , wherein the lamella surface is structured at least in the last one-third of the headbox nozzle.  
     
     
         4 . The process in accordance with  claim 3 , wherein the lamella surface is structured over its entire length.  
     
     
         5 . The process in accordance with  claim 2 , wherein the lamella surface is structured in a region of a nozzle discharge opening.  
     
     
         6 . The process in accordance with  claim 5 , wherein the lamella surface is structured in a lip area of the nozzle discharge opening.  
     
     
         7 . The process in accordance with  claim 5 , wherein the lamella surface is structured exclusively in the region of the nozzle discharge opening.  
     
     
         8 . The process in accordance with,  claim 7 , wherein the lamella surface is structured exclusively in the lip area of the nozzle discharge opening.  
     
     
         9 . The process ill accordance with  claim 2 , wherein the at least one structure is arranged at an angle of between 0° and 90° to a machine running direction.  
     
     
         10 . The process in accordance with  claim 9 , wherein the at least one structure is arranged at an angle of between 20° and 70° to the machine running direction.  
     
     
         11 . The process in accordance with  claim 2 , wherein the at least one structure is curved so that the suspension steam is tangentially aimed at the structures in a machine running direction and is subsequently diverted at an angle of 0° to 90°.  
     
     
         12 . The process in accordance with  claim 2 , wherein the at least one lamella extends through a nozzle opening to outside of the headbox nozzle.  
     
     
         13 . The process in accordance with  claim 2 , wherein the at least one structure has a length/width ratio (L/B)>2.  
     
     
         14 . The process in accordance with  claim 2 , wherein the at least one lamella is structured continuously up to a lamella tip.  
     
     
         15 . The process in accordance with  claim 2 , wherein the at least one lamella comprises at least two lamella arranged so that one side of each lamella face each other, and the process further comprises: 
 providing the at least one structure on each of the facing sides of the at least two lamella.    
     
     
         16 . The process in accordance with  claim 15 , wherein the at least one structure provided on the two facing sides of the at least two lamella are arranged to be oppositely oriented.  
     
     
         17 . The process in accordance with  claim 2 , wherein the at least one structure comprises a recess formed in the at least one lamella.  
     
     
         18 . The process in accordance with  claim 2 , wherein the at least one structure comprises a structure raised above the surface of the lamella.  
     
     
         19 . The process in accordance with  claim 2 , wherein the at least one structure comprises a curved flow guide element.  
     
     
         20 . The process in accordance with  claim 2 , wherein the at least one structure is located inside the headbox nozzle.  
     
     
         21 . The process in accordance with  claim 20 , wherein the at least one structure is provided in a last one-third of the headbox nozzle viewed in a flow direction.  
     
     
         22 . The process in accordance with  claim 2 , wherein the at least one structure is comprises a plurality of structures arranged to generate flows running towards one another, thereby balancing one another.  
     
     
         23 . The process in accordance with  claim 2 , wherein the at least one lamella is arranged to form a multi-layer headbox, and the at least one structure comprises a plurality of structures arranged to generate unidirectional flows.  
     
     
         24 . A headbox for performing the process in accordance with  claim 2 , wherein said headbox nozzle is defined by at least one wall, and said at least one wall comprises at least one structure one of in and on a wall surface arranged to face the pulp suspension stream.  
     
     
         25 . The process in accordance with  claim 2 , wherein the at least one lamella comprises at least two lamellae having sides arranged to face each other and each of the at least two lamellae includes at least one structure, and the at least one structures are at least one of arranged on facing sides of the at least two lamellae to interlock or fit together are provided on facing sides of adjacent lamellae and arranged on facing sides of at least one of the at least two lamellae and a nozzle wall to interlock or fit together.  
     
     
         26 . The process in accordance with  claim 2 , further comprising selecting at least one of a length of the at least one lamella and one of a depth or height of the at least one structure to adjust certain shear flows.  
     
     
         27 . The process in accordance with  claim 26 , wherein the one of the depth or height of the at least one structure is arranged in a region of the nozzle opening.  
     
     
         28 . The process in accordance with  claim 26 , wherein the depth of the at least one structure has a value in the range of 5% to 95% of a flow channel enclosed by the at least one lamella.  
     
     
         29 . The process in accordance with  claim 28 , wherein the depth has a value in the range of 20% to 80% of the flow channel enclosed by the lamella.  
     
     
         30 . The process in accordance with  claim 26 , wherein the depth of the at least one structure has a value in the range of 1% to 99% of a thickness of the lamella.  
     
     
         31 . The process in accordance with  claim 30 , wherein the depth has a value in the range of 10% to 95% of the lamella thickness.  
     
     
         32 . The process in accordance with  claim 26 , wherein a height of the at least one structure has a value in the range of 1% to 99% of the flow channel enclosed by the lamella.  
     
     
         33 . The process in accordance with  claim 32 , wherein the height has a value in the range of 20% to 80% of the flow channel enclosed by the lamella.  
     
     
         34 . The process in accordance with  claim 2 , wherein the at least one structure comprises a plurality of structures and the at least one lamella further includes a partition in the range of 0.5 mm to 20 mm between the plurality of structures, in which the partition range is at least one of constant or different in at least one of the machine or cross machine directions.  
     
     
         35 . The process in accordance with  claim 34 , wherein the partition range is between 2 mm and 10 mm.  
     
     
         36 . The process in accordance with  claim 2 , wherein the headbox comprises a multi-layer headbox, and the process further comprises charging a middle layer of the multi-layer headbox with long-fibered material to increase the strength.  
     
     
         37 . A headbox of a machine for performing the process in accordance with  claim 2  to produce a fibrous material web, said headbox comprising: 
 the headbox nozzle;  
 the at least one lamella being located within said headbox nozzle having a structured surface at least in some areas comprising at least one structure arranged at least one of in and on said surface of said at least one lamella; and  
 said structured surface being arranged to generate cross flows inside a suspension stream, whereby the cross flows lead to shear flows in the suspension stream.  
 
     
     
         38 . A headbox of a machine for producing a fibrous material web to form one of a paper or cardboard web, comprising: 
 a headbox nozzle;    at least one lamella located within said headbox nozzle, having a structured surface at least in some areas comprising at least one structure arranged at least one of in and on said surface of said at least one lamella; and    said structured surface being arranged to generate cross flows inside a suspension stream, whereby the cross flows lead to shear flows in the suspension stream.    
     
     
         39 . The headbox in accordance with  claim 38 , wherein said surface of said at least one lamella is structured at least in a last third of said headbox nozzle.  
     
     
         40 . The headbox in accordance with  claim 39 , wherein said surface is structured over its entire length.  
     
     
         41 . The headbox in accordance with  claim 38 , wherein said surface of said at least one lamella is structured in a region of a nozzle discharge opening.  
     
     
         42 . The headbox in accordance with  claim 41 , wherein said surface is structured in a region of a lip of said nozzle discharge opening.  
     
     
         43 . The headbox in accordance with  claim 41 , wherein said surface of said at least one lamella is structured exclusively in a region of a nozzle discharge opening.  
     
     
         44 . The headbox in accordance with  claim 43 , wherein said surface is structured exclusively in a region of a lip of said nozzle discharge opening.  
     
     
         45 . The headbox in accordance with  claim 38 , wherein the at least one structure is arranged at an angle of 0° to 90° to a machine direction.  
     
     
         46 . The headbox in accordance with  claim 45 , wherein said at least one structure is arranged at an angle of 20° to 70° to the machine direction.  
     
     
         47 . The headbox in accordance with  claim 38 , wherein said at least one structure comprises a curved structure arranged so that the suspension stream is tangentially aimed at said at least one structure in a machine direction and is subsequently diverted at an angle of 0° to 90°.  
     
     
         48 . The headbox in accordance with  claim 38 , wherein said at least one lamella extends through a nozzle opening to outside of said headbox nozzle.  
     
     
         49 . The headbox in accordance with  claim 38 , wherein said at least one structure has a length/width ratio (L/B)>2.  
     
     
         50 . The headbox in accordance with  claim 38 , wherein said at least one lamella is structured continuously up to a lamella tip.  
     
     
         51 . The headbox in accordance with  claim 38 , wherein said at least one lamella comprises at least two lamellae having sides arranged to face each other, and each of said facing sides comprise said structured surface.  
     
     
         52 . The headbox in accordance with  claim 51 , wherein said at least one structures on the facing sides of the at least two lamellae are arranged to be oppositely oriented.  
     
     
         53 . The headbox in accordance with  claim 38 , wherein said at least one structure comprises a recess formed in said at least one lamella.  
     
     
         54 . The headbox in accordance with  claim 38 , wherein said at least one structure comprises a structure raised above said surface of said at least one lamella.  
     
     
         55 . The headbox in accordance with  claim 38 , wherein said at least one structure comprises a curved flow guide element.  
     
     
         56 . The headbox in accordance with  claim 38 , wherein said at least one structure is located inside said headbox nozzle.  
     
     
         57 . The headbox in accordance with  claim 38 , wherein said at least one structure is located in a last third of said headbox nozzle viewed in a flow direction.  
     
     
         58 . The headbox in accordance with  claim 38 , wherein said at least one structure comprises a plurality of structures arranged to generate flows running towards one another, thereby balancing one another.  
     
     
         59 . The headbox in accordance with  claim 38 , wherein said headbox comprises a multi-layer headbox, and said structured surface is arranged to generate unidirectional flows.  
     
     
         60 . The headbox in accordance with  claim 38 , wherein said headbox nozzle is delimited by at least one wall, and said at least one wall comprises a structured surfaces arranged to face the pulp suspension stream.  
     
     
         61 . The headbox in accordance with  claim 38 , wherein said at least one lamella comprises at least two lamellae having sides arranged to face each other and each of the at least two lamellae includes a structured surface, and said structured surfaces are at least one of arranged to face each other with structures of said structured surfaces arranged to interlock or fit together or arranged on facing sides of one at least one of the lamella and a nozzle wall with structures of said structured surface and wall arranged to interlock or fit together.  
     
     
         62 . The headbox in accordance with  claim 38 , wherein a depth of said at least one structure has a value in a range of 5% to 95% of a flow channel enclosed by said at least one lamella.  
     
     
         63 . The headbox in accordance with  claim 62 , wherein said depth has a value in the range of 20% to 80% of the flow channel enclosed by said lamella.  
     
     
         64 . The headbox in accordance with  claim 38 , wherein a depth of said at least one structure has a value in a range of 1% to 99% of a thickness of said at least one lamella.  
     
     
         65 . The headbox in accordance with  claim 64 , wherein said depth has a value in the range of 10% to 95% of said lamella thickness.  
     
     
         66 . The headbox in accordance with  claim 38 , wherein a height of said at least one structure has a value in the range of 1% to 99% of said flow channel enclosed by said at least one lamella.  
     
     
         67 . The headbox in accordance with  claim 66 , wherein said height has a value in the range of 20% to 80% of the flow channel enclosed by said lamella.  
     
     
         68 . The headbox in accordance with  claim 38 , wherein said structured surface comprises at least two structures separated by a partition, and said partition has a distance or thickness in a range of 0.5 mm to 20 mm, in which the partition range is at least one of constant or different in at least one of a machine and a cross machine direction.  
     
     
         69 . The headbox in accordance with  claim 68 , wherein said partition distance or thickness is in the range of 2 mm to 10 mm.  
     
     
         70 . The headbox in accordance with  claim 38 , wherein said headbox comprises a multi-layer headbox arranged to be charged with long-fibered material.  
     
     
         71 . The headbox in accordance with  claim 70 , wherein a middle layer in said multi-layer headbox is charged with the long-fibered material.